Torque arm assembly for nip rollers

ABSTRACT

A nip roller assembly for a laundry machine having an upper driven roller and a lower driving roller wherein the driven roller is journaled to the frame of the laundry machine and the driving roller is vertically movable with respect to the laundry machine. The driving roller is vertically guided within a vertical channel and is raised into engagement with the driven roller by hydraulic rams. The loading torque on the vertically movable driving roller is absorbed by a torque arm and link assembly attached between the frame of the laundry machine and a roller bearing supporting the driving roller.

De adman [451 Mar. 11, 1975 l l TORQUE ARM ASSEMBLY FOR NIP ROLLERS [76] Inventor: Vernon E. Deadman, 36 Allerford [52] US. Cl 68/258, 68/269 R, 74/380, 74/431, 74/387, 100/172 [51] Int. Cl. D06f 45/00 [58] Field of Search 68/253 R, 258, 269 R, 249, 68/244, DIG. 3, DIG. 5; 100/172, 170, 176, 163 A; 74/387, 383, 380, 411, 431, 17

[56] References Cited UNITED STATES PATENTS 2,453,279 11/1948 Starbuck 74/380 2,758,466 8/1956 Belcher 1 68/258 2,851,869 9/1958 Quoos et al 68/258 3,237,428 3/1966 Witt 74/431 Primary Examiner-Harvey C. Hornsby Attorney, Agent, or Firm-Sandoe, Hopgood & Calimafde [57] ABSTRACT A nip roller assembly for a laundry machine having an upper driven roller and a lower driving roller wherein the driven roller is journaled to the frame of the laundry machine and the driving roller is vertically movable with respect to the laundry machine. The driving roller is vertically guided within a vertical channel and is raised into engagement with the driven roller by hydraulic rams. The loading torque on the vertically movable driving roller is absorbed by a torque arm and link assembly attached between the frame of the laundry machine and a roller bearing supporting the driving roller.

6 Claims, 3Drawing Figures PATENTED 1I975 3.869.884

same 952 FI G E 20 TORQUE ARM ASSEMBLY FOR NIP ROLLERS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to pressure rollers and more particularly to the mounting of pressure rollers within a laundry machine.

2. Description of the Prior Art Pressure rollers, or nip rollers, have long been used for compressing flat articles in many industrial processes including laundry applications. Usually the rollers act in pairs with one roller journaled to a supporting frame for the whole assembly and the other roller movable with respect to the journaled roller. The movable roller is usually movable in a direction perpendicular to the flow of articles through the machine and is forced under pressure against the fixed roller. The perpendicular motion or the movable roller is required to provide for variations in the thickness of the articles passing between the rollers.

In most installations the roller that is not indepen' dently powered, commonly called the driven roller, is movably mounted with respect to the frame. The other roller that is independently powered by an exterior motor, commonly called the driving roller, is journaled to the frame to prevent any rectilinear motion with re spect to the frame. The fixed driving roller can then be attached by just a simple coupling to a stationary driving motor through a stationary gear box. in these installations the motor, gear box and driving roller have no relative motion with respect to each other.

In other applications, specifically in the textile and paper mill industries, the driving roller is movable and the driven roller is fixed with respect to the frame. This arrangement is just the reverse of the one described above. in these textile and paper mill installations the gear boxes connecting the driving rollers to a stationary driving motor are fixed with respect to the frame and also the driven rollers. Hence, the rectilinear movement between any two nip rollers is accommodated by a flexible coupling between the fixed gear box and the movable driving roller.

in these prior art installations, the nip roller assemblies have generally required complicated gear mechanisms and complex supporting arrangements. In order to provide a nip roller assembly capable of maintaining a constant tangential speed or constant processing speed and also allowing for compensation for varying thicknesses of material passing between the rollers, very complex equipment has been required. Each nip roller assembly must maintain a constant processing speed so that the articles passing therethrough can be fed evenly from one roller assembly to the next. In addition, the complexity of this equipment has correspondingly made it more difficult to remove the nip rollers for resurfacing and replacement. During normal operation one or both nip rollers may wear down and ultimately require either resurfacing of their cylindrical surfaces or replacement thereof. Having complex gearing and driving mechanisms attached to each roller assembly requires that the mechanisms be both removed and remounted during each maintenance cycle a time consuming process. Finally, the initial cost of each nip roller assembly is substantial because of the large production and design effort expended on the gear mechanism.

SUMMARY OF THE lNVENTlON In a pressure roller, or nip roller, assembly having a driven roller disposed over a driving roller for squeezing flat articles passing through a laundry machine. the driving roller is vertically movable with respect to the laundry machine within a mounting frame for the roller assembly. The driven roller, having no independent source of power, is journaled to the frame of the laundry machine and is thereby prohibited from making any rectilinear motion with respect to the laundry machine.

The driving roller is preferably connected to a stationary driving motor by a gear box, universaljoint, and a torque shaft. The vertical movement of the driving roller is guided by vertical channels in the mounting frame of the roller assembly. The gear box is inflexibly mounted to the driving roller and is vertically movable therewith. A torque arm, attached to the gear box, and a connecting link, attached between the frame of the laundry machine and the torque arm, are preferably used to absorb the loading torque on the roller assembly while permitting vertical movement of the driving rollers. The driving roller is elevated into operable engagement with the driven roller by pressure applying means located below the bearings supporting the driving roller.

The primary object of the present invention is to construct a nip roller assembly that is easily maintainable even though one of the rollers must be formed of resilient material in order to provide the requisite resilient squeezing pressure upon the material passing through the rollers. To this end, the upper roller is fabricated from a resilient material which will ultimately wear, and the lower roller is fabricated from hard, very durable, long wearing material. Under normal operating conditions all of the wear on a complimentary pair of nip rollers, occurs on the upper roller. Thus, when routine resurfacing or replacement of the nip rollers is required, it is only the upper roller that is removed. The upper roller is more easily removable from the laundry machine for maintenance and repair than heretofore possible. The upper roller is located near the top of the laundry machine and is easily accessible by removing an access cover plate. The upper roller is not buried deep within the laundry machine among the water tanks and piping and is not attached to the pressure applying means. Moreover, the upper roller is not independently powered, so the upper roller does not have a power transmitting coupling or a gear box to be disconnected when it is to be removed. For easy removal the upper roller can be merely journaled to the frame of the laundry machine.

Another object of the present invention is to maintain the nip rollers at a constant linear, tangential speed. Maintaining the same constant tangential speed for each nip roller assembly is essential so that the articles passing through the laundry machine are evenly fed from one roller assembly to the next. According to the present invention each driving roller is manufactured with a hard, very durable surface to maintain a constant radial dimension. Thus, when all of the driving rollers for all of the nip roller assemblies are geared together, the same constant tangential speed for each roller assembly is maintained.

A further object of the present invention is to provide for the separation of the nip rollers upon a loss of power or upon shut down. In emergency situations the nip rollers will always separate under the force of gravity, and thus their disengagement is less subject to mechanical failure. For a normal shut-down the rollers should be separated to insure that the rollers do not develop flat spots on the engaged cylindrical surfaces. In the present invention the rollers automatically separate because the lower roller is elevated into operable engagement with the upper roller by two vertical rams. When the rams are depressurized, the lower roller descends out of engagement under the force of gravity.

An additional object of the present invention is to provide a simple and effective torque absorbing assembly. In the present invention the gear box for each nip roller assembly moves with the driving roller, and both the gear box and the driving roller are restrained together. The torque is absorbed by the combination of a torque arm connected to the gear box and a connecting link attached between the torque arm and the frame of the laundry machine.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic perspective of two nip roller assemblies in a laundry machine each having a torque arm assembly, certain parts being broken away and others shown in section;

FIG. 2 is a vertical section, taken along line 22 of FIG. 1, of the two nip rollers in one nip roller assembly and the associated torque arm assembly in the laundry machine; and

FIG. 3 is a top plan view of the nip roller assemblies of FIG. 1 showing one of the upper nip rollers in one assembly and one of the lower nip rollers in an adjacent assembly, certain parts being broken away and others shown in section.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, reference numeral 12 (FIG. 1) generally indicates a frame. The frame provides the requisite supporting structure for a pair of nip roller assemblies 13. The frame includes a front wall 14, a rear wall 16 and a segmented top covering plate 18. The top covering plate includes removable access plates 20 that provide accessibility to the inside of the machine.

The preferred embodiment of the present invention was constructed for use in a continuous process laundry machine. Such a continuous process laundry machine is disclosed in US Pat. No. 3,505,004 entitled Washing and Like Treatments of Textile Fibres and Materials and issued to Allan F. Pfeil on Apr. 7, 1970. Additionally, in the preferred embodiment of the invention constructed for the continuous process laundry machine the nip roller assemblies engage the material being laundered while it is carried by a continuous filament conveyor 21. Such a continuous filament conveyor is disclosed in US. Pat. No. 3,598,226 entitled Conveyors and issued to Lawrence F. I-Iayman on Aug. 10, 1971.

The front wall 14 and the rear wall 16 of the laundry machine are further divided by a plurality of vertical slots 22,22. Each vertical slot 22 in the front wall is in registry with a vertical slot 22' in the rear wall. On each inward facing, vertical sidewall of the slots 22,22 is a vertical guide 24. The vertical guides are rectangular in cross section (FIG. 3) and are fabricated from high strength plastic. The vertical guides form two vertical tracks within the vertical slots to direct the vertical movement of the nip rollers as hereinafter described.

Within each pair of front and rear vertical slots 22,22, respectively, is a complimentary pair of pressure rollers 26 and 28. The pressure rollers are also commonly called nip rollers and are used to compress flat articles passing therebetween. The flat articles are conveyed from one pair of nip rollers 13 to the next pair by the continuous filament conveyor 21 movable in the direction shown by the arrows in FIG. 1. Reference numeral 26 indicates the upper driven roller and reference numeral 28 indicates the lower driving roller. Each pair of nip rollers is maintained in vertical alignment by the vertical slots 22,22. The driven roller 26 has no independent source of power, and the driving roller 28 is independently motorized as hereinafter described.

Each driven roller 26 includes an outside surface 30 and an inner core 32. The outside surface is manufactured from a deformable, wearable material such as natural rubber having a durometer readingof Shore.

The inner core 32 forms the axle of the driven roller and can be manufactured from steel. The driven roller is supported at each end by a bearing 34. Each bearing is a self-aligning roller bearing of conventional construction and is rigidly attached to the front wall 14 and the rear wall 16 by a pair of retaining plates 36 which are bolted directly to the walls by bolts 37. The retaining plates permit the driven roller 26 to rotate freely about its longitudinal axis but prohibit any rectilinear motion of the driven roller with respect to the laundry machine. For routine replacement or resurfacing of a driven roller the retaining plates are designed for easy and rapid detachment from the walls by removing the bolts 37, and the driven roller 26 can be removed through the opening provided by removing the top access plate 20. When the driven roller is removed from the frame 12 of the laundry machine, the bearings 34 slide up the vertical slots 22,22 about the vertical guides 24 (FIG. 3).

As for each driving roller 28, which is located below its associated driven roller 26, such driving roller includes an outside surface 38 and a core 40. The outside surface of the driving roller is long wearing, very durable and substantially non-deformable. The outside surface can be manufactured from a hard rubber material such as ebonite. The core 40 of the roller forms an axle for the driving roller and can be manufactured from any high strength material such as steel. The driving roller is supported at each end by a bearing 42. Each bearing 42 is a conventional, self-aligning roller bearing similar to the bearing 34. The bearings for the driving roller are slidably received within the vertical slots 22,22 and are vertically directed by the vertical guides 24. Thus, while the driven roller 26 is fixed with respect to the frame, the driving roller 28 is vertically movable within the frame of the laundry machine.

Each driving roller 28 is vertically moved within vertical slots 22,22 by a pair of hydraulic rams 44 (see FIG. 2). The hydraulic rams are of conventional construction and are operated together by conventional hydraulic control circuitry (not shown) to simultaneously elevate two operating arms or piston rods 46 which directly support the lower faces of the bearings 42. The hydraulic rams are rigidly attached at their bases to the frame 12. When the hydraulic rams are pressurized, the operating arms elevate the bearings 42 and thereby raise the driving roller into operational engagement with the fixed driven roller 26 at a predeter mined uniform pressure.

Each driving roller 28 is powered through a gear box 48. The gear box houses a conventional worm gear having a gear ratio of 30 to 1. The gear box is powered by a torque shaft 50 having a universal joint 52 between each set of nip roller assemblies. The gear box for each driving roller is inflexibly mounted thereto. When the hydraulic rams 44 elevate the bearings 42 for the driving roller, the gear box is also elevated. The mechanical flexure in the torque shaft created by the vertical movement of the driving roller is absorbed by the adjacent universal joint. The torque shaft is rotated by a driving pulley 54 (FIG. 1) that is turned by a plurality of belts 56. The driving rollers, the gear boxes and the driving pulley are all powered through the belts by a main drive motor 58. Reference numeral 60 (FIG. 1) indicates an idler pulley which is mounted on a spring-loaded arm and which is used to maintain a tension on the belts despite any shifting of the driving pulley 54 due to vertical movement of the torque shaft. The motor 58 is a conventional electric motor having sufficient power to turn a plurality of nip rollers. In the preferred embodiment constructed for use in the continuous process laundry machine, the motor drives four nip roller assemblies only two of which are shown in FIG. 1.

The reaction torque developed by each driving roller 28 is absorbed by a torque arm assembly 61. The

' torque arm assembly includes a torque arm 62 that is rigidly attached to the gear box 48. The torque arm is generally shaped like a right triangle with its vertical side edge facing in the direction of the oncoming flow of articles passing through the nip rollers. Pivotally mounted at the upper end of the apex of the torque arm 62 is a pair of parallel, generally horizontal, connecting links 64. The connecting links are also pivotally mounted to a pad eye 66. The pad eye is rigidly affixed to the front wall 14 of the frame 12 of the laundry machine. Both the torque arm and the pad eye are pivotally connected to the connecting links through resilient rubber cushions (not shown) that resiliently damp in shear the reaction torque-and the vertical motion of the nip rollers. Thus, the driving roller is permitted to move vertically within the vertical slots 22,22 and the gear box is prevented from rotating by the torque arm as sembly.

When the nip roller assemblies are shut down, the hydraulic rams 44 are depressurized and the associated operating arms 46 are retracted downward. The driving rollers 28 with their bearings 42 that rest on top of two operating arms are also retracted downward out of engagement with the associated driven rollers 26. The multiple filaments of the continuous filament conveyor 21 remain in place but are not engaged by either roller.

To place the nip roller assemblies into operation, the hydraulic rams 44 are initially pressurized to elevate the driving rollers into operational engagement with the driven rollers 26. The operating arms 46 of the hydraulic rams extend and the bearings 42 of the driving roller slide vertically upward within the vertical slots 22,22 along the vertical guides 24. The gear boxes 48 are also elevated by the hydraulic rams 44 because the gear boxes are inflexibly coupled to their associated driving rollers and move therewith. The combined vertical movement of each gear box and driving roller is compensated for by the universal joints 52 and the resilient flexible connections of the torque arm assembly 61 In operation each nip roller assembly compresses all of the flat articles passing between the driven roller 26 and the driving roller 28. The hydraulic rams 44 force the rollers together so that a substantial compression pressure is achieved. In the preferred embodiment constructed for the continuous process laundry machine, the compression of the nip rollers is used to drive the continuous filament conveyor.

As the rollers engage the articles passing therethrough, the driven roller remains fixed with respect to the frame. While operatively engaging the driven roller, the driving roller moves vertically up and down to accommodate the varying thickness of the incoming articles. The hydraulic rams are used to maintain a constant pressure between the two rollers ofeach nip roller assembly. Although the driven roller 26 remains fixed with respect to the frame because of the retaining plates 36, the driven roller rotates either by the frictional engagement with the driving roller or by the frictional engagement with the articles passing between the two rollers.

As hereinbefore described, the driving roller 28 has a hard, durable, outside surface 38. Because the outside surface does not wear down, the radius of the driving roller does not change substantially. Thus, the tangential speed of the driving roller is always the same assuming a constant driving speed of the motor 58. For an apparatus containing a plurality of nip roller assemblies, the tangential speed of all of the nip rollers can thereby be easily synchronized and maintained in that condition.

In contrast, the driven roller is fabricated from a softer material so that any wear in the nip roller assemblies will occur on the driven roller. When the driven roller has become excessively worn and requires replacement, the driven roller is easily removed through the openings in the top plate 18 provided by the access plate 20 as hereinbefore described. The easy removal of a driven roller permits a minimum shut down time and reduces the cost of roller replacement.

To shut down the nip roller assembly, the motor 58 is stopped and the hydraulic rams 44 are automatically depressurized. The two rollers of each nip roller assembly separate in order to prevent the development of a longitudinal flat spot along the point of engagement. The operating arms 46 of the hydraulic rams retract downwardly, and the bearings 42 supporting the lower driving roller also slide downwardly along the vertical guides 24 in the vertical slots 22,22. The downward motion of the driving roller 28 and the associated gear box 48 is accommodated by the universal joints 52 and the torque arm assembly 61.

Although the best mode contemplated for carrying out the present invention has been herein disclosed and described, it will be apparent that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.

What is claimed is:

1. A nip-roller assembly for compressing articles passing through a laundry machine, comprising spaced upstanding side-frame members between which laundry articles are to be conducted along a longitudinal path of continuous movement, a plurality of longitudinally spaced pairs of nip rollers supported by and between said frame members and along said path, each pair comprising a lower driving roller and an upper driven roller, means providing fixed bearing support in said frame members for the respective ends of the driven rollers, means providing vertically floating and upwardly pressure-loaded bearing support guided with respect to said side-frame members and independent for the respective ends of the driving rollers, a separate housed reduction-gear mechanism having output connection to each driving roller at one side frame, each gear mechnism and its housing thus floating with the end of the driving roller which it serves, the input-shaft alignments of adjacent reduction-gear mechanisms being generally horizontally aligned, universal-coupling means interconnecting the inputs to said adjacent gear mechanisms, torque-reacting link means for each gear housing and pivotally interconnecting a point on the adjacent side-frame member to a point on the applicable gear housing, said point of connection to the applicable gear housing being offset in elevation from the associated drive-roller axis, and said point of connection to the side-frame member being essentially horizontally offset from the gear housing connection point, whereby said reduction-gear mechanisms may be driven in unison with uniform output speeds while independently elevated to maintain constant loading pressure on passing laundry articles of varying thickness.

2. In a nip roller assembly for compressing articles passing through a laundry machine which includes a frame for mounting the nip roller assembly; a motor for powering said assembly; means for coupling the motor to the assembly whereby the motor operatively drives the assembly under varying loads; a driving roller connected by the coupling means to the motor and driven thereby; bearing means for rotationally supporting the driving roller with respect to the frame; a driven roller operably engageable by the driving roller and driven thereby; bearing means for rotationally supporting the driven roller with respect to the frame; and means for mounting bearing means for the driven roller and the driving roller on the frame whereby the driven roller and the driving roller are operably retained therein, the improvement in the means for mounting the bearing means comprising: fixed mountings for the bearing means of the driven roller whereby the driven roller is prohibited from rectilinear movement, said driven roller being positioned vertically above said driving roller; means for vertically moving the bearing means of the driving roller on command whereby the driving roller can be brought into operational engagement with the driven roller; said motor coupling to said assembly including a housed gear assembly having an output connection on the alignment of and carried at one end of said driving roller, whereby said gear assembly and its housing are caused to track in elevation the rise and fall of said driving roller, and torque-reaction means including a generally horizontal rigid link pivotally connected at one end to a point on the frame and pivotally connected at its other end to said gear housing at a point offset in elevation with respect to the axis of said driving roller, whereby reaction torque occasioned by power transmission through said gear assembly is directly referenced to said frame over a range of drivingroll elevation.

3. In a nip roller assembly as set forth in claim 2 wherein said driven roller has a resilient wearable surface and wherein said driving roller has a hard nonwearing surface.

4. In a nip roller assembly as set forth in claim 2 wherein said means for mounting each bearing means of said driving roller comprises a pair of opposed vertically extending guide members, each bearing means for the driving roller being provided with a pair of slots slidably mounted upon said guide members.

5. A nip roller assembly as set forth in claim 2. in which said gear assembly includes an input shaft on a generally horizontal alignment which is substantially perpendicular to the rise-and-fall movement of said driving roller, and means including a universal joint coupling said motor to said input shaft.

6. In a nip roller assembly for compressing articles passing through a laundry machine which includes a frame for mounting the nip roller assembly; a motor powering said assembly; means for coupling the motor to the assembly whereby the motor operatively drives the assembly under varying loads; a driving roller connected by the coupling means to the motor and driven thereby, said coupling means including a gear assembly carried by one end of said driving roller and having an output connection on the alignment of said driving roller; bearing means for rotationally supporting the driving roller with respect to the frame; a driven roller operably engageable by the driving roller and driven thereby; bearing means for rotationally supporting the driven roller with respect to the frame; and means for mounting the driven bearing means and the driving bearing means on the frame whereby the driven roller and the driving roller are operably retained therein, the improvement in the means for mounting the bearing means comprising: fixed mountings for the bearing means of the driven roller whereby the driven roller is prohibited from rectilinear movement, said driven roller being positioned vertically above said driving roller; at least one vertical hydraulic ram rigidly attached to the frame and having an operating arm supporting from below the bearing means for the driving roller whereby the said driving roller and its bearing means and said gear assembly are commandably raisable for operational contact of the driving and driven rollers; a plurality of vertical channels for the bearing means for the driving roller for guiding the vertical motion of its bearing means within the frame; a pad eye member rigidly mounted to the frame and having an attachable free end; a non-deformable link having two attachable free ends and having one free end attached to the free end of the pad eye by a first coupling; and a nondeformable arm member rigidly attached to said gear assembly and attached to the other free end of the link by a second coupling, the points of link connection by said first and second couplings being similarly offset in their elevation with respect to the elevation of the driving-roller axis, whereby said pad eye member, link, first coupling, second coupling and arm member absorb any loading torque placed on the driving roller. 

1. A nip-roller assembly for compressing articles passing through a laundry machine, comprising spaced upstanding sideframe members between which laundry articles are to be conducted along a longitudinal path of continuous movement, a plurality of longitudinally spaced pairs of nip rollers supported by and between said frame members and along said path, each pair comprising a lower driving roller and an upper driven roller, means providing fixed bearing support in said frame members for the respective ends of the driven rollers, means providing vertically floating and upwardly pressure-loaded bearing support guided with respect to said side-frame members and independent for the respective ends of the driving rollers, a separate housed reduction-gear mechanism having output connection to each driving roller at one side frame, each gear mechanism and its housing thus floating with the end of the driving roller which it serves, the input-shaft alignments of adjacent reduction-gear mechanisms being generally horizontally aligned, universal-coupling means interconnecting the inputs to said adjacent gear mechanisms, torque-reacting link means for each gear housing and pivotally interconnecting a point on the adjacent side-frame member to a point on the applicable gear housing, said point of connection to the applicable gear housing being offset in elevation from the associated drive-roller axis, and said point of connection to the side-frame member being essentially horizontally offset from the gear housing connection point, whereby said reduction-gear mechanisms may be driven in unison with uniform output speeds while independently elevated to maintain constant loading pressure on passing laundry articles of varying thickness.
 1. A nip-roller assembly for compressing articles passing through a laundry machine, comprising spaced upstanding side-frame members between which laundry articles are to be conducted along a longitudinal path of continuous movement, a plurality of longitudinally spaced pairs of nip rollers supported by and between said frame members and along said path, each pair comprising a lower driving roller and an upper driven roller, means providing fixed bearing support in said frame members for the respective ends of the driven rollers, means providing vertically floating and upwardly pressure-loaded bearing support guided with respect to said side-frame members and independent for the respective ends of the driving rollers, a separate housed reduction-gear mechanism having output connection to each driving roller at one side frame, each gear mechanism and its housing thus floating with the end of the driving roller which it serves, the input-shaft alignments of adjacent reduction-gear mechanisms being generally horizontally aligned, universal-coupling means interconnecting the inputs to said adjacent gear mechanisms, torque-reacting link means for each gear housing and pivotally interconnecting a point on the adjacent side-frame member to a point on the applicable gear housing, said point of connection to the applicable gear housing being offset in elevation from the associated drive-roller axis, and said point of connection to the side-frame member being essentially horizontally offset from the gear housing connection point, whereby said reduction-gear mechanisms may be driven in unison with uniform output speeds while independently elevated to maintain constant loading pressure on passing laundry articles of varying thickness.
 2. In a nip roller assembly for compressing articles passing through a laundry machine which includes a frame for mounting the nip roller assembly; a motor for powering said assembly; means for coupling the motor to the assembly whereby the motor operatively drives the assembly under varying loads; a driving roller connected by the coupling means to the motor and driven thereby; bearing means for rotationally supporting the driving roller with respect to the frame; a driven roller operably engageable by the driving roller and driven thereby; bearing means for rotationally supporting the driven roller with respect to the frame; and means for mounting bearing means for the driven roller and the driving roller on the frame whereby the driven roller and the driving roller are operably retained therein, the improvement in the means for mounting the bearing means comprising: fixed mountings for the bearing means of the driven roller whereby the driven roller is prohibited from rectilinear movement, said driven roller being positioned vertically above said driving roller; means for vertically moving the bearing means of the driving roller on command whereby the driving roller can be brought into operational engagement with the driven roller; said motor coupling to said assembly including a housed gear assembly having an output connection on the alignment of and carried at one end of said driving roller, whereby said gear assembly and its housing are caused to track in elevation the rise and fall of said driving roller, and torque-reaction means including a generally horizontal rigid link pivotally connected at one end to a point on the frame and pivotally connected at its other end to said gear housing at a point offset in elevation with respect to the axis of said driving roller, whereby reaction torque occasioned by power transmission through said gear assembly is directly referenced to said frame over a range of driving-roll elevation.
 3. In a nip roller assembly as set forth in claim 2 wherein said driven roller has a resilient wearable surface and wherein said driving roller has a hard non-wearing surface.
 4. In a nip roller assembly as set forth in claim 2 wherein said means for mounting each bearing means of said driving roller comprises a pair of opposed vertically extending guide members, each bearing means for the driving roller being provided with a pair of slots slidably mounted upon said guide members.
 5. A nip roller assembly as set forth in claim 2, in which said gear assembly includes an input shaft on a generally horizontal alignment which is substantially perpendicular to the rise-and-fall movement of said driving roller, and means including a universal joint coupling said motor to said input shaft. 